Durham University | 2017 Mar 21
[c][youtube]https://www.youtube.com/watch?v=bPxUKuB5_zY[/youtube]This movie follows the formation of galaxies with cosmic time, illustrating how UVAstronomers have developed a way to detect the ultraviolet (UV) background of the universe, which could help explain why there are so few small galaxies in the cosmos.
radiation from other galaxies and from quasars suppresses the formation of stars
inside small galaxies near to large galaxies similar to the Milky Way and Andromeda.
The left panel shows a simulation that includes such diffuse UV radiation as in the
real Universe, where fewer smaller galaxies form. For comparison, the right panel
shows what would happen in the absence of such radiation, with more small galaxies
forming. Credit: S. McAlpine/S. Berry[/c][hr][/hr]
UV radiation is invisible but shows up as visible red light when it interacts with gas.
An international team of researchers led by Durham University, UK, has now found a way to measure it using instruments on Earth.
The researchers said their method can be used to measure the evolution of the UV background through cosmic time, mapping how and when it suppresses the formation of small galaxies.
The study could also help produce more accurate computer simulations of the evolution of the universe. ...
A measurement of the z = 0 UV background from Hα fluorescence - Michele Fumagalli et al
- Monthly Notices of the RAS 467(4):4802 (June 2017) DOI: 10.1093/mnras/stx398
arXiv.org > astro-ph > arXiv:1702.04726 > 15 Feb 2017 (v1), 04 Mar 2017 (v2)